Search for Invisible Decays of a Higgs Boson Produced in Association with a Z Boson in ATLAS
Search for Invisible Decays of a Higgs Boson Produced in Association with a Z Boson in ATLAS
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在 ATLAS 中寻找与 Z 玻色子相关产生的希格斯玻色子的不可见衰变
DOI：
10.1103/physrevlett.112.201802
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发表时间：
2014-05-20
影响因子：
8.6
通讯作者：
Zurzolo, G.
中科院分区：
文献类型：
--
作者：
Aad, G.;Abajyan, T.;Zurzolo, G.
提出了在大型强子对撞机中与Z玻色子联合产生的希格斯玻色子的不可见粒子衰变模式的证据。在ATLAS实验收集的7 (8)TeV pp碰撞数据中，4.5 fb(-1) （20.3 fb(-1)）未观察到与标准模型期望的偏差。假设ZH产生的标准模型速率，上限为75%，在95%的置信水平上设定了质量为125.5 GeV的希格斯玻色子与不可见粒子衰变模式的分支比。分支比的限制也被解释为在希格斯-入口暗物质场景中允许的暗物质-核子散射截面的上限。在这种情况的约束下，这封信中提出的结果为低质量暗物质候选者提供了最强的可用限制。另外还有一个中性希格斯玻色子，其质量范围为110 < m(H) < 400 GeV，与Z玻色子一起产生，并衰变成不可见的粒子。
A search for evidence of invisible-particle decay modes of a Higgs boson produced in association with a Z boson at the Large Hadron Collider is presented. No deviation from the standard model expectation is observed in 4.5 fb(-1) (20.3 fb(-1)) of 7 (8) TeV pp collision data collected by the ATLAS experiment. Assuming the standard model rate for ZH production, an upper limit of 75%, at the 95% confidence level is set on the branching ratio to invisible-particle decay modes of the Higgs boson at a mass of 125.5 GeV. The limit on the branching ratio is also interpreted in terms of an upper limit on the allowed dark matter-nucleon scattering cross section within a Higgs-portal dark matter scenario. Within the constraints of such a scenario, the results presented in this Letter provide the strongest available limits for low-mass dark matter candidates. Limits are also set on an additional neutral Higgs boson, in the mass range 110 < m(H) < 400 GeV, produced in association with a Z boson and decaying to invisible particles.